Hydroxycitric acid, both free acid and lactone forms, is present in the fruit rind, of Garcinia species (e.g., Garcinia cambogia, Garcinia atroviridis, and Garcinia indica), which are commercially available in India.
As an inhibitor of the synthesis of fat and cholesterol, hydroxycitric acid has been shown to significantly reduce the body weight and lower lipid accumulation in rats. See, e.g., Sergio, W., Medical Hypothesis 27: 39 (1988); and Sullivan, A. C. et al., Lipids 9: 121 (1973); and Sullivan, A. C. et al., Lipids 9: 129 (1973). Hydroxycitric acid is also the only known anorectic agent found as a natural constituent of edible foods consumed by humans.
Methods for the extraction and purification of hydroxycitric acid from Garcinia rind can be found in Lewis, Y. S., Methods in Enzymology 13: 613 (1967); and Indian Patent No. 160753.